SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c10bb551832fb279ecbbe56e27c8280db36028ec3c9a1a47f821da8254615680' 
  AND token = 'SbjLti0eT4CJDO8YUSMeFfZEmFttOyj9SsjjE1dl9Ww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}